Subgroups of autistic children based on social behavior display distinct patterns of brain activity

Two questions were addressed in the present study: (1) Do autistic and normally developing children exhibit regionally specific differences in electroencephalographic (EEG) activity? (2) Do subgroups of autistic children classified according to Wing and Gould's (1979) system which emphasizes degree of social impairment exhibit distinct patterns of EEG activity? Twenty-eight children with autism (5 to 18 years of age) and two groups of normally developing children (one matched on chronological age and the other on receptive language level) participated. EEG was recorded from left and right frontal, temporal, and parietal regions during an alert baseline condition. Compared to normally developing children, autistic children exhibited reduced EEG power in the frontal and temporal regions, but not in the parietal region. Differences were more prominent in the left than the right hemisphere. Furthermore, subgroups of autistic children based on Wing and Gould's system displayed distinct patterns of brain activity. Compared to autistic children classified as “active-but-odd,” “passive” autistic children displayed reduced alpha EEG power in the frontal region.     

Are research subjects adequately protected? A review and discussion of studies conducted by the Advisory Committee on Human Radiation Experiments

In light of information uncovered about human radiation experiments conducted during the Cold War, an important charge for the Advisory Committee on Human Radiation Experiments was to assess the current state of protections for human research subjects. This assessment was designed to enhance the Committee's ability to make informed recommendations for the improvement of future policies and practices for the protection of research subjects. The Committee's examination of current protections revealed great improvement over those from the past, yet some problems remain. Although the data collected by the Committee highlight specific areas in need of attention, the Committee's work should be viewed in part as the beginning of a series of ongoing assessments of the adequacy and effectiveness of the protections afforded to human subjects.     

Prepulse effects on magnitude estimation of startle-eliciting stimuli and startle responses

The present studies investigated the relationship between prepulse effects on the modification of the brainstem startle reflex and magnitude estimates of startle-eliciting stimuli. In Experiment 1, startle eyeblink responses were elicited in 24 students, half of whom were instructed to estimate the loudness of the startle stimulus (actual intensities of 80, 90, and 100 dB) and half of whom were instructed to estimate the magnitude of their eyeblink. When weak acoustic prepulses preceded the startle-eliciting stimulus, eyeblink amplitude was inhibited, and estimates of response magnitude decreased, but estimates of startle stimulus magnitude decreased only when 100-dB startle stimuli were presented. In Experiment 2, the same startle stimuli were preceded on some trials by a vibrotactile prepulse to the hand. In conditions in which startle amplitude was inhibited, startle stimulus magnitude estimates were not affected. This suggests that the effect of acoustic prepulses on 100-dB startle stimuli in Experiment 1 may have been due to loudness assimilation, an effect independent of the prepulse inhibition of startle responding.     

Behavior of neonates exposed in utero to methadone as assessed on the Brazelton scale

Twenty-nine infants exposed in utero to methadone and 37 comparison infants were examined on the Neonatal Behavioral Assessment Scale at early and late neonatal ages. All infants were full-term at birth, over 2500 g, and not yet circumcised at the early assessment. None of the methadone-exposed infants were breast-fed or were being treated pharmacologically for withdrawal. During the first week of life, methadone-exposed neonates differed from comparison ones in motoric behavior. Relative to comparison-group infants, they were jerkier and more tremulous, tense, active, and better able to put hand in mouth. By the end of the first month these differences diminished, although there was still a tendency for the methadone-exposed infants to have elevated body tonus. Neither perinatal complications, birth weight, nor sex of infant could explain the early neonatal differences between the methadone and comparison groups. Past the early stage of acute withdrawal, neonates exposed prenatally to methadone behave not unlike their nonexposed peers.     

The effect of object shape and mode of presentation on judgments of apparent volume

Apparent volume for geometric solids and life-sized two dimensional representations of these solids was scaled by magnitude estimation. Data were adequately fit by power functions whose exponents were less than those previously reported for judgments of apparent length and area. Object shape and mode of presentation affected both magnitude estimations of apparent volume and the best fitting power function exponents. The influence of shape, both across object shape classes and within the cylinder shape class, appears to depend upon the relative elongation of the vertical dimension.     

VideoNoter: A productivity tool for video data analysis

The software described in this paper, VideoNoter, addresses the need for tools that support annotation and retrieval of video data and organize the presentation of multiple analyses of the same data. Video is widely perceived as an important medium for psychological research, because video recording makes the fleeting particulars of human interaction available as data for detailed analysis, while retaining much of the context of the event. Though the benefits of using video data are high, the process can be prohibitively time-consuming. We have developed a prototype computer-based video analysis tool that can enhance the productivity of the video analysis process. In this paper, we report on the design and implementation of VideoNoter, and we discuss how it facilitates video data analysis.     

Cerebral lateralization in individuals diagnosed as autistic in early childhood

Early infantile autism was found to be associated with an atypical pattern of cerebral lateralization. Based on EEG measures of hemispheric activation during cognitive processing, it was found that 7 of the 10 autistic individuals tested showed a pattern of hemispheric specialization rarely seen in the normal population; namely, a “reversal” in lateralization reflective of a lack of left-hemisphere specialization for linguistic functions. Furthermore, the autistic individuals' pattern of cognitive strengths and weakness is suggestive of a selective impairment of the left cerebral hemisphere.     

Electrodermal responses to attended and nonattended significant stimuli during dichotic listening

Some investigators have found that words previously associated with shock elicit electrodermal responses (EDRs) when presented in the nonattended channel of a dichotic listening task. The present experiment tested for this phenomenon while closely monitoring for shifts in attention to the nonattended channel. College student volunteers verbally shadowed a series of unrelated words presented to the attended channel while words made significant by previous association with shock (and semantically related words) were occasionally presented to the nonattended channel. Three principal findings were obtained. Fist, when EDRs were averaged across all trials and across all subjects, it was found that EDRs were elicited by the significant words presented in the nonattended channel. Second, for the subgroup of subjects that had the significant words presented to the right ear (activating the left cerebral hemisphere), it was found that EDRs were elicited by the significant words presented to the left ear (activating the right cerebral hemisphere), it was found that EDRs were elicited by the significant word seven on trials on which there were no apparent shifts in attention. The results of this study indicate the importance of closely controlling and monitoring for shifts in attention and suggest the potential importance of cerebral laterality in mediating EDRs to stimuli presented in a nonatttended channel.